IRQ not firing when in SVC call


so I'm currently working on a kernel-call delay implementation. Now the delay function is really very simple and just a timer counting down.

The svc call is issued form EL0 and trapped to EL1 where the delay fn is implemented. Now my problem is that when I'm in EL1 for longer amount of time, the timer irq(which calls the scheduler) fires while I'm still in the timers svc call.

Since the timer irq is not fired when I'm in el1, the scheduler does not get called and the process is stuck. Generally when I'm in a kernel process(so EL1) the timer irq does still get called, only when I'm in the svc call it doesn't.

I'm specifically enabling irqs in the daif reg before counting down, which other config regs could conflict?

Regards NIklas